1. WARM UP 01/09/17 Go over the words and write the Definition of each:
Point postulate
line plane
collinear coplanar
segment endpoint
ray opposite rays

2. Review and go over Quiz items:
Use the diagram at the right. 1.
Name the points on plane S.
ANSWER
F, K, and Q 2.
Name two lines.
ANSWER
a and b 3.
Name the plane that contains point D.
ANSWER
plane P or plane DFQ

3. Use the diagram at the right.4.
Name three collinear points.
ANSWER
F, Q, and W 5.
Decide whether the following
statement is true or false.
Points K, F, and D are coplanar.
ANSWER
true

4. ESSENTIAL Question
-How do you Identify & Sketch Intersections?

5. VOCABULARY
In geometry, figures intersect if they have any points in common.
The intersection of two or more figures is the point or points that the figures have in common.

7. Intersection of Two Lines
POSTULATE
Postulate:
Intersection of Two Lines
If two lines intersect, then their intersection is a point.

9. Use the diagram at the right.
Example 1
Name Intersections of Lines
Use the diagram at the right. c.
Name the intersection of AC and DF. a.
Name the intersection of AC and BE. b.
Name the intersection of BE and DF.
SOLUTION a.
point B. b.
point E. c.
AC and DF do not appear to intersect. 9

10. Intersection of Two Planes
POSTULATE
Intersection of Two Planes
If two planes intersect, then their intersection is a line.

12. In the diagram, planes R, S, & T are intersecting.
Example 2
Name Intersections of Planes
In the diagram, planes R, S, & T are intersecting. b.
Name the intersection of planes R and T. a.
Name the intersection of planes S and R. c.
Name the intersection of planes T and S.
SOLUTION a.
at line k. b.
Planes R and T do not intersect. c.
at line l. 12

13. Sketch a plane. Then sketch each of the following.
Example 3
Sketch Intersections of Lines and Planes
Sketch a plane. Then sketch each of the following. a.
a line that is in the plane b.
a line that does not intersect the plane c.
a line that intersects the plane at a point
SOLUTION a.
Draw the plane. Then draw a line in the plane. 13

14. Draw the plane. Then draw a line above or below the plane.
Example 3
Sketch Intersections of Lines and Planes b.
Draw the plane. Then draw a line above or below the plane. c.
Draw the plane. Then draw a line that intersects the plane. 14

15. Homework